LOLOLOLOLOLOLOLOLOL. Biden would run his traditional gaffe-prone campaign. It wouldn't be a landslide because of Christie's baggage, but Biden would definitely lose. I'd be expecting something like this:
Christie 285-253Christie comes off as bullyish and mean. Not to mention he is publicly perceived as a crook. Once voters imagine him dealing with Putin or even our allies in Europe, they'll see Dubya-level potential to wreck international relationships.
I didn't take Biden gaffe-prone-ness into account much though. It might be closer than this, but I really don't see anything resulting in a Christie win. And when Christie goes off on people in his audience, I think that equals a gaffe. I'd like to see him pull that "sit down and shut up" shi.t in the town hall debate.